|  | #ifndef _LINUX_KPROBES_H | 
|  | #define _LINUX_KPROBES_H | 
|  | /* | 
|  | *  Kernel Probes (KProbes) | 
|  | *  include/linux/kprobes.h | 
|  | * | 
|  | * This program is free software; you can redistribute it and/or modify | 
|  | * it under the terms of the GNU General Public License as published by | 
|  | * the Free Software Foundation; either version 2 of the License, or | 
|  | * (at your option) any later version. | 
|  | * | 
|  | * This program is distributed in the hope that it will be useful, | 
|  | * but WITHOUT ANY WARRANTY; without even the implied warranty of | 
|  | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the | 
|  | * GNU General Public License for more details. | 
|  | * | 
|  | * You should have received a copy of the GNU General Public License | 
|  | * along with this program; if not, write to the Free Software | 
|  | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | 
|  | * | 
|  | * Copyright (C) IBM Corporation, 2002, 2004 | 
|  | * | 
|  | * 2002-Oct	Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel | 
|  | *		Probes initial implementation ( includes suggestions from | 
|  | *		Rusty Russell). | 
|  | * 2004-July	Suparna Bhattacharya <suparna@in.ibm.com> added jumper probes | 
|  | *		interface to access function arguments. | 
|  | * 2005-May	Hien Nguyen <hien@us.ibm.com> and Jim Keniston | 
|  | *		<jkenisto@us.ibm.com>  and Prasanna S Panchamukhi | 
|  | *		<prasanna@in.ibm.com> added function-return probes. | 
|  | */ | 
|  | #include <linux/linkage.h> | 
|  | #include <linux/list.h> | 
|  | #include <linux/notifier.h> | 
|  | #include <linux/smp.h> | 
|  | #include <linux/bug.h> | 
|  | #include <linux/percpu.h> | 
|  | #include <linux/spinlock.h> | 
|  | #include <linux/rcupdate.h> | 
|  | #include <linux/mutex.h> | 
|  |  | 
|  | #ifdef CONFIG_KPROBES | 
|  | #include <asm/kprobes.h> | 
|  |  | 
|  | /* kprobe_status settings */ | 
|  | #define KPROBE_HIT_ACTIVE	0x00000001 | 
|  | #define KPROBE_HIT_SS		0x00000002 | 
|  | #define KPROBE_REENTER		0x00000004 | 
|  | #define KPROBE_HIT_SSDONE	0x00000008 | 
|  |  | 
|  | /* Attach to insert probes on any functions which should be ignored*/ | 
|  | #define __kprobes	__attribute__((__section__(".kprobes.text"))) | 
|  | #else /* CONFIG_KPROBES */ | 
|  | typedef int kprobe_opcode_t; | 
|  | struct arch_specific_insn { | 
|  | int dummy; | 
|  | }; | 
|  | #define __kprobes | 
|  | #endif /* CONFIG_KPROBES */ | 
|  |  | 
|  | struct kprobe; | 
|  | struct pt_regs; | 
|  | struct kretprobe; | 
|  | struct kretprobe_instance; | 
|  | typedef int (*kprobe_pre_handler_t) (struct kprobe *, struct pt_regs *); | 
|  | typedef int (*kprobe_break_handler_t) (struct kprobe *, struct pt_regs *); | 
|  | typedef void (*kprobe_post_handler_t) (struct kprobe *, struct pt_regs *, | 
|  | unsigned long flags); | 
|  | typedef int (*kprobe_fault_handler_t) (struct kprobe *, struct pt_regs *, | 
|  | int trapnr); | 
|  | typedef int (*kretprobe_handler_t) (struct kretprobe_instance *, | 
|  | struct pt_regs *); | 
|  |  | 
|  | struct kprobe { | 
|  | struct hlist_node hlist; | 
|  |  | 
|  | /* list of kprobes for multi-handler support */ | 
|  | struct list_head list; | 
|  |  | 
|  | /*count the number of times this probe was temporarily disarmed */ | 
|  | unsigned long nmissed; | 
|  |  | 
|  | /* location of the probe point */ | 
|  | kprobe_opcode_t *addr; | 
|  |  | 
|  | /* Allow user to indicate symbol name of the probe point */ | 
|  | const char *symbol_name; | 
|  |  | 
|  | /* Offset into the symbol */ | 
|  | unsigned int offset; | 
|  |  | 
|  | /* Called before addr is executed. */ | 
|  | kprobe_pre_handler_t pre_handler; | 
|  |  | 
|  | /* Called after addr is executed, unless... */ | 
|  | kprobe_post_handler_t post_handler; | 
|  |  | 
|  | /* | 
|  | * ... called if executing addr causes a fault (eg. page fault). | 
|  | * Return 1 if it handled fault, otherwise kernel will see it. | 
|  | */ | 
|  | kprobe_fault_handler_t fault_handler; | 
|  |  | 
|  | /* | 
|  | * ... called if breakpoint trap occurs in probe handler. | 
|  | * Return 1 if it handled break, otherwise kernel will see it. | 
|  | */ | 
|  | kprobe_break_handler_t break_handler; | 
|  |  | 
|  | /* Saved opcode (which has been replaced with breakpoint) */ | 
|  | kprobe_opcode_t opcode; | 
|  |  | 
|  | /* copy of the original instruction */ | 
|  | struct arch_specific_insn ainsn; | 
|  |  | 
|  | /* | 
|  | * Indicates various status flags. | 
|  | * Protected by kprobe_mutex after this kprobe is registered. | 
|  | */ | 
|  | u32 flags; | 
|  | }; | 
|  |  | 
|  | /* Kprobe status flags */ | 
|  | #define KPROBE_FLAG_GONE	1 /* breakpoint has already gone */ | 
|  | #define KPROBE_FLAG_DISABLED	2 /* probe is temporarily disabled */ | 
|  | #define KPROBE_FLAG_OPTIMIZED	4 /* | 
|  | * probe is really optimized. | 
|  | * NOTE: | 
|  | * this flag is only for optimized_kprobe. | 
|  | */ | 
|  |  | 
|  | /* Has this kprobe gone ? */ | 
|  | static inline int kprobe_gone(struct kprobe *p) | 
|  | { | 
|  | return p->flags & KPROBE_FLAG_GONE; | 
|  | } | 
|  |  | 
|  | /* Is this kprobe disabled ? */ | 
|  | static inline int kprobe_disabled(struct kprobe *p) | 
|  | { | 
|  | return p->flags & (KPROBE_FLAG_DISABLED | KPROBE_FLAG_GONE); | 
|  | } | 
|  |  | 
|  | /* Is this kprobe really running optimized path ? */ | 
|  | static inline int kprobe_optimized(struct kprobe *p) | 
|  | { | 
|  | return p->flags & KPROBE_FLAG_OPTIMIZED; | 
|  | } | 
|  | /* | 
|  | * Special probe type that uses setjmp-longjmp type tricks to resume | 
|  | * execution at a specified entry with a matching prototype corresponding | 
|  | * to the probed function - a trick to enable arguments to become | 
|  | * accessible seamlessly by probe handling logic. | 
|  | * Note: | 
|  | * Because of the way compilers allocate stack space for local variables | 
|  | * etc upfront, regardless of sub-scopes within a function, this mirroring | 
|  | * principle currently works only for probes placed on function entry points. | 
|  | */ | 
|  | struct jprobe { | 
|  | struct kprobe kp; | 
|  | void *entry;	/* probe handling code to jump to */ | 
|  | }; | 
|  |  | 
|  | /* For backward compatibility with old code using JPROBE_ENTRY() */ | 
|  | #define JPROBE_ENTRY(handler)	(handler) | 
|  |  | 
|  | /* | 
|  | * Function-return probe - | 
|  | * Note: | 
|  | * User needs to provide a handler function, and initialize maxactive. | 
|  | * maxactive - The maximum number of instances of the probed function that | 
|  | * can be active concurrently. | 
|  | * nmissed - tracks the number of times the probed function's return was | 
|  | * ignored, due to maxactive being too low. | 
|  | * | 
|  | */ | 
|  | struct kretprobe { | 
|  | struct kprobe kp; | 
|  | kretprobe_handler_t handler; | 
|  | kretprobe_handler_t entry_handler; | 
|  | int maxactive; | 
|  | int nmissed; | 
|  | size_t data_size; | 
|  | struct hlist_head free_instances; | 
|  | raw_spinlock_t lock; | 
|  | }; | 
|  |  | 
|  | struct kretprobe_instance { | 
|  | struct hlist_node hlist; | 
|  | struct kretprobe *rp; | 
|  | kprobe_opcode_t *ret_addr; | 
|  | struct task_struct *task; | 
|  | char data[0]; | 
|  | }; | 
|  |  | 
|  | struct kretprobe_blackpoint { | 
|  | const char *name; | 
|  | void *addr; | 
|  | }; | 
|  |  | 
|  | struct kprobe_blackpoint { | 
|  | const char *name; | 
|  | unsigned long start_addr; | 
|  | unsigned long range; | 
|  | }; | 
|  |  | 
|  | #ifdef CONFIG_KPROBES | 
|  | DECLARE_PER_CPU(struct kprobe *, current_kprobe); | 
|  | DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); | 
|  |  | 
|  | /* | 
|  | * For #ifdef avoidance: | 
|  | */ | 
|  | static inline int kprobes_built_in(void) | 
|  | { | 
|  | return 1; | 
|  | } | 
|  |  | 
|  | #ifdef CONFIG_KRETPROBES | 
|  | extern void arch_prepare_kretprobe(struct kretprobe_instance *ri, | 
|  | struct pt_regs *regs); | 
|  | extern int arch_trampoline_kprobe(struct kprobe *p); | 
|  | #else /* CONFIG_KRETPROBES */ | 
|  | static inline void arch_prepare_kretprobe(struct kretprobe *rp, | 
|  | struct pt_regs *regs) | 
|  | { | 
|  | } | 
|  | static inline int arch_trampoline_kprobe(struct kprobe *p) | 
|  | { | 
|  | return 0; | 
|  | } | 
|  | #endif /* CONFIG_KRETPROBES */ | 
|  |  | 
|  | extern struct kretprobe_blackpoint kretprobe_blacklist[]; | 
|  |  | 
|  | static inline void kretprobe_assert(struct kretprobe_instance *ri, | 
|  | unsigned long orig_ret_address, unsigned long trampoline_address) | 
|  | { | 
|  | if (!orig_ret_address || (orig_ret_address == trampoline_address)) { | 
|  | printk("kretprobe BUG!: Processing kretprobe %p @ %p\n", | 
|  | ri->rp, ri->rp->kp.addr); | 
|  | BUG(); | 
|  | } | 
|  | } | 
|  |  | 
|  | #ifdef CONFIG_KPROBES_SANITY_TEST | 
|  | extern int init_test_probes(void); | 
|  | #else | 
|  | static inline int init_test_probes(void) | 
|  | { | 
|  | return 0; | 
|  | } | 
|  | #endif /* CONFIG_KPROBES_SANITY_TEST */ | 
|  |  | 
|  | extern int arch_prepare_kprobe(struct kprobe *p); | 
|  | extern void arch_arm_kprobe(struct kprobe *p); | 
|  | extern void arch_disarm_kprobe(struct kprobe *p); | 
|  | extern int arch_init_kprobes(void); | 
|  | extern void show_registers(struct pt_regs *regs); | 
|  | extern kprobe_opcode_t *get_insn_slot(void); | 
|  | extern void free_insn_slot(kprobe_opcode_t *slot, int dirty); | 
|  | extern void kprobes_inc_nmissed_count(struct kprobe *p); | 
|  |  | 
|  | #ifdef CONFIG_OPTPROBES | 
|  | /* | 
|  | * Internal structure for direct jump optimized probe | 
|  | */ | 
|  | struct optimized_kprobe { | 
|  | struct kprobe kp; | 
|  | struct list_head list;	/* list for optimizing queue */ | 
|  | struct arch_optimized_insn optinsn; | 
|  | }; | 
|  |  | 
|  | /* Architecture dependent functions for direct jump optimization */ | 
|  | extern int arch_prepared_optinsn(struct arch_optimized_insn *optinsn); | 
|  | extern int arch_check_optimized_kprobe(struct optimized_kprobe *op); | 
|  | extern int arch_prepare_optimized_kprobe(struct optimized_kprobe *op); | 
|  | extern void arch_remove_optimized_kprobe(struct optimized_kprobe *op); | 
|  | extern void arch_optimize_kprobes(struct list_head *oplist); | 
|  | extern void arch_unoptimize_kprobes(struct list_head *oplist, | 
|  | struct list_head *done_list); | 
|  | extern void arch_unoptimize_kprobe(struct optimized_kprobe *op); | 
|  | extern kprobe_opcode_t *get_optinsn_slot(void); | 
|  | extern void free_optinsn_slot(kprobe_opcode_t *slot, int dirty); | 
|  | extern int arch_within_optimized_kprobe(struct optimized_kprobe *op, | 
|  | unsigned long addr); | 
|  |  | 
|  | extern void opt_pre_handler(struct kprobe *p, struct pt_regs *regs); | 
|  |  | 
|  | #ifdef CONFIG_SYSCTL | 
|  | extern int sysctl_kprobes_optimization; | 
|  | extern int proc_kprobes_optimization_handler(struct ctl_table *table, | 
|  | int write, void __user *buffer, | 
|  | size_t *length, loff_t *ppos); | 
|  | #endif | 
|  |  | 
|  | #endif /* CONFIG_OPTPROBES */ | 
|  |  | 
|  | /* Get the kprobe at this addr (if any) - called with preemption disabled */ | 
|  | struct kprobe *get_kprobe(void *addr); | 
|  | void kretprobe_hash_lock(struct task_struct *tsk, | 
|  | struct hlist_head **head, unsigned long *flags); | 
|  | void kretprobe_hash_unlock(struct task_struct *tsk, unsigned long *flags); | 
|  | struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk); | 
|  |  | 
|  | /* kprobe_running() will just return the current_kprobe on this CPU */ | 
|  | static inline struct kprobe *kprobe_running(void) | 
|  | { | 
|  | return (__this_cpu_read(current_kprobe)); | 
|  | } | 
|  |  | 
|  | static inline void reset_current_kprobe(void) | 
|  | { | 
|  | __this_cpu_write(current_kprobe, NULL); | 
|  | } | 
|  |  | 
|  | static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void) | 
|  | { | 
|  | return (&__get_cpu_var(kprobe_ctlblk)); | 
|  | } | 
|  |  | 
|  | int register_kprobe(struct kprobe *p); | 
|  | void unregister_kprobe(struct kprobe *p); | 
|  | int register_kprobes(struct kprobe **kps, int num); | 
|  | void unregister_kprobes(struct kprobe **kps, int num); | 
|  | int setjmp_pre_handler(struct kprobe *, struct pt_regs *); | 
|  | int longjmp_break_handler(struct kprobe *, struct pt_regs *); | 
|  | int register_jprobe(struct jprobe *p); | 
|  | void unregister_jprobe(struct jprobe *p); | 
|  | int register_jprobes(struct jprobe **jps, int num); | 
|  | void unregister_jprobes(struct jprobe **jps, int num); | 
|  | void jprobe_return(void); | 
|  | unsigned long arch_deref_entry_point(void *); | 
|  |  | 
|  | int register_kretprobe(struct kretprobe *rp); | 
|  | void unregister_kretprobe(struct kretprobe *rp); | 
|  | int register_kretprobes(struct kretprobe **rps, int num); | 
|  | void unregister_kretprobes(struct kretprobe **rps, int num); | 
|  |  | 
|  | void kprobe_flush_task(struct task_struct *tk); | 
|  | void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head); | 
|  |  | 
|  | int disable_kprobe(struct kprobe *kp); | 
|  | int enable_kprobe(struct kprobe *kp); | 
|  |  | 
|  | void dump_kprobe(struct kprobe *kp); | 
|  |  | 
|  | #else /* !CONFIG_KPROBES: */ | 
|  |  | 
|  | static inline int kprobes_built_in(void) | 
|  | { | 
|  | return 0; | 
|  | } | 
|  | static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr) | 
|  | { | 
|  | return 0; | 
|  | } | 
|  | static inline struct kprobe *get_kprobe(void *addr) | 
|  | { | 
|  | return NULL; | 
|  | } | 
|  | static inline struct kprobe *kprobe_running(void) | 
|  | { | 
|  | return NULL; | 
|  | } | 
|  | static inline int register_kprobe(struct kprobe *p) | 
|  | { | 
|  | return -ENOSYS; | 
|  | } | 
|  | static inline int register_kprobes(struct kprobe **kps, int num) | 
|  | { | 
|  | return -ENOSYS; | 
|  | } | 
|  | static inline void unregister_kprobe(struct kprobe *p) | 
|  | { | 
|  | } | 
|  | static inline void unregister_kprobes(struct kprobe **kps, int num) | 
|  | { | 
|  | } | 
|  | static inline int register_jprobe(struct jprobe *p) | 
|  | { | 
|  | return -ENOSYS; | 
|  | } | 
|  | static inline int register_jprobes(struct jprobe **jps, int num) | 
|  | { | 
|  | return -ENOSYS; | 
|  | } | 
|  | static inline void unregister_jprobe(struct jprobe *p) | 
|  | { | 
|  | } | 
|  | static inline void unregister_jprobes(struct jprobe **jps, int num) | 
|  | { | 
|  | } | 
|  | static inline void jprobe_return(void) | 
|  | { | 
|  | } | 
|  | static inline int register_kretprobe(struct kretprobe *rp) | 
|  | { | 
|  | return -ENOSYS; | 
|  | } | 
|  | static inline int register_kretprobes(struct kretprobe **rps, int num) | 
|  | { | 
|  | return -ENOSYS; | 
|  | } | 
|  | static inline void unregister_kretprobe(struct kretprobe *rp) | 
|  | { | 
|  | } | 
|  | static inline void unregister_kretprobes(struct kretprobe **rps, int num) | 
|  | { | 
|  | } | 
|  | static inline void kprobe_flush_task(struct task_struct *tk) | 
|  | { | 
|  | } | 
|  | static inline int disable_kprobe(struct kprobe *kp) | 
|  | { | 
|  | return -ENOSYS; | 
|  | } | 
|  | static inline int enable_kprobe(struct kprobe *kp) | 
|  | { | 
|  | return -ENOSYS; | 
|  | } | 
|  | #endif /* CONFIG_KPROBES */ | 
|  | static inline int disable_kretprobe(struct kretprobe *rp) | 
|  | { | 
|  | return disable_kprobe(&rp->kp); | 
|  | } | 
|  | static inline int enable_kretprobe(struct kretprobe *rp) | 
|  | { | 
|  | return enable_kprobe(&rp->kp); | 
|  | } | 
|  | static inline int disable_jprobe(struct jprobe *jp) | 
|  | { | 
|  | return disable_kprobe(&jp->kp); | 
|  | } | 
|  | static inline int enable_jprobe(struct jprobe *jp) | 
|  | { | 
|  | return enable_kprobe(&jp->kp); | 
|  | } | 
|  |  | 
|  | #endif /* _LINUX_KPROBES_H */ |